Question about addon image file paths

This is probably a pretty basic question, but if I have an image file in the same folder as my addon init file, what do i need to put as a path so that other users can also access this image through the addon? I realize that having my direct C:\ path will not work for other users, while having just the image name “plane1.jpg” does not seem to work, so it seems that i need to use some other path system to always have access to this image. Any help is greatly appreciated!

Does this help?


Thanks so much!